40 Series Muffler

Add Flowmaster's most aggressive-sounding muffler to your system with the Flowmaster 40 Series Muffler

Flowmaster builds your 40 Series Muffler from aluminized steel for high corrosion resistance

Precision mig welds provide maximum durability

The Flowmaster 40 Series Muffler is ideal for off-road vehicles, racers, early muscle cars, and dual exhaust systems

Classic two-chamber design boosts your horsepower and torque

Variety of configurations and sizes to fit most vehicles

Flowmaster name embossed on the casing

3-Year Warranty

The classic Flowmaster 40 Series Muffler puts some real punch in your vehicle. The 40 Series is the original aggressive Flowmaster muffler, with maximized horsepower and torque gains. Plus, you get the massive roaring exhaust sound that made Flowmaster famous.

The Flowmaster 40 Series is made especially for those who love a big aggressive-sounding engine. The outside tone is loud and bold, and the high-volume interior resonance reacts to every nuance of your gas pedal. This sound-enhancing design is the reason the Flowmaster 40 Series is at the core of many Flowmaster American Thunder Exhaust Systems. The Flowmaster 40 Series is designed especially to satisfy those who drive classic muscle cars, dual exhaust rides, and off-road machines. Their 16-gauge aluminized steel and fully mig-welded construction resists corrosion and stands up for years of use and abuse.

Choose from a variety of sizes and inlet/outlet configurations for your Flowmaster Series 40 Muffler, and enjoy the feel of an American original. Backed by a 3-Year Warranty.

Flowmaster 40 Series Muffler Customer Reviews

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Flow master is Great! I Love the fact that my truck is nice and loud now!

Install Time: 30-60 minutes

Shawn W2015-07-29

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This is a great sounding muffler. It was not direct fit on my 2014 Ram. After some pipe bending and about 45 minutes I was all set. Now I love it!

Install Time: 30-60 minutes

Bert L2013-07-24

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I have a 2006 Dodge Ram SLT Quad Cab 2500 pickup truck. I purchased a Flowmaster 40 Series Muffler from Auto Accessories and installed it six days ago. Let me tell you the Flowmaster Muffler along with the Spectrum cold air intake is the best investment I made so far for my truck. I have increased power and speed and it sounds great. Most of all I am really enjoying the increase in gas mileage. Originally I was getting 9.5 miles to a gallon in the city and 16 miles to the gallon on the highway. With my new muffler and cold air intake I now get an average of 21 miles to a gallon in the city and 30 miles to a gallon on the highway. What a difference and with gas prices being over 4 dollars per gallon this is a big savings. Give the Flomaster 40 Series and the Spectrum Cold Air Intake a try you won't regret it.

Install Time: 1-2 hours

chevy #12011-11-21

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Great sounding muffler! Glad I bought a Flowmaster. No other sound like it around.

Install Time: 30-60 minutes

MATTHEW C2011-09-28

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Great product and seller, installed in under 30 mins, happy about this purchase.